Abstract
The purpose of this thesis is to experimentally generate periodic surface structures on the metal substrate (Both STAVAX stainless mold and Ni-coated STAVAX stainless mold) by femtosecond laser-induced periodic surface structure (FLIPSS) technique. First, a structured metal template was fabricated by femtosecond laser with proper laser fluence, repetition rate, and scanning speed by Ytterbium femtosecond laser system. After the template had been fabricated, it was used as a mold to transfer structure to the polymer plate by sub-micro imprinting method, then the plate’s reflectance and transmittance was measured in visible light region. As the result, FLIPSS’s period can mainly dependent on fs-laser fluence and number of pulses. The period will become smaller as number of pulses increase and laser fluence decrease. Besides, the structure profile can also be changed with fluence and scanning speed. The structure types can be divided into two types. One only has the direction perpendicular to scanning direction. The structure is formed by lower fs-laser fluence and slower scanning speed with the period close to 900 nm. Another has both perpendicular and parallel directions. Furthermore, the formation of the structures can be determined by higher laser fluence and lower scanning speed with the period from 2 to 5 μm. Combination of FLIPSS and sub-micro imprinting method (including hot-embossing and injection molding) can successfully transfer the periodic structures to polymer template in an area of 8 mm by 8 mm. FLIPSS on PMMA plate can reduced reflectance about 3 to 4 % in visible light region, but FLIPSS on COC plate unfortunately reduce the transmittance about 10% to 50% in visible light region. The future prospect of this research is promising to rapidly transfer functional sub-microstructure with smaller period on polymer. Hoping FLIPSS technique can improve the process of imprinting or other industrial applications.